An inverter apparatus which drives an onboard electric motor constitutes a high-voltage system, and a control apparatus which controls the inverter apparatus constitutes a low-voltage system insulated from the high-voltage system. When a signal indicative of temperature information on switching elements constituting the inverter apparatus or abnormality information indicative of an abnormality in any of the switching elements is transmitted from the inverter apparatus to the control apparatus, the signal is transmitted from the high-voltage system to the low-voltage system. Since the high-voltage system and the low-voltage system are insulated from each other, signal transmission from the inverter apparatus to the control apparatus is performed via an insulation element.
PTL 1 describes a configuration which transmits a signal indicative of temperature information and a signal indicative of abnormality information via a common insulating terminal in order to reduce the number of insulation elements used.